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a28b2bfc09
The cppc_cpudata per-cpu storage was inefficient (1) additional to causing
functional issues (2) when CPUs are hotplugged out, due to per-cpu data
being improperly initialised.
(1) The amount of information needed for CPPC performance control in its
cpufreq driver depends on the domain (PSD) coordination type:
ANY: One set of CPPC control and capability data (e.g desired
performance, highest/lowest performance, etc) applies to all
CPUs in the domain.
ALL: Same as ANY. To be noted that this type is not currently
supported. When supported, information about which CPUs
belong to a domain is needed in order for frequency change
requests to be sent to each of them.
HW: It's necessary to store CPPC control and capability
information for all the CPUs. HW will then coordinate the
performance state based on their limitations and requests.
NONE: Same as HW. No HW coordination is expected.
Despite this, the previous initialisation code would indiscriminately
allocate memory for all CPUs (all_cpu_data) and unnecessarily
duplicate performance capabilities and the domain sharing mask and type
for each possible CPU.
(2) With the current per-cpu structure, when having ANY coordination,
the cppc_cpudata cpu information is not initialised (will remain 0)
for all CPUs in a policy, other than policy->cpu. When policy->cpu is
hotplugged out, the driver will incorrectly use the uninitialised (0)
value of the other CPUs when making frequency changes. Additionally,
the previous values stored in the perf_ctrls.desired_perf will be
lost when policy->cpu changes.
Therefore replace the array of per cpu data with a list. The memory for
each structure is allocated at policy init, where a single structure
can be allocated per policy, not per cpu. In order to accommodate the
struct list_head node in the cppc_cpudata structure, the now unused cpu
and cur_policy variables are removed.
For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1,
(4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows:
Before patch:
- ANY coordination:
total slack req alloc/free caller
0 0 0 0/1 _kernel_size_le_hi32+0x0xffff800008ff7810
0 0 0 0/6 _kernel_size_le_hi32+0x0xffff800008ff7808
128 80 48 1/0 _kernel_size_le_hi32+0x0xffff800008ffc070
768 0 768 6/0 _kernel_size_le_hi32+0x0xffff800008ffc0e4
After patch:
- ANY coordination:
total slack req alloc/free caller
256 0 256 2/0 _kernel_size_le_hi32+0x0xffff800008fed410
0 0 0 0/2 _kernel_size_le_hi32+0x0xffff800008fed274
Additional notes:
- A pointer to the policy's cppc_cpudata is stored in policy->driver_data
- Driver registration is skipped if _CPC entries are not present.
Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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| .. | ||
| acpi-cpufreq.c | ||
| amd_freq_sensitivity.c | ||
| armada-8k-cpufreq.c | ||
| armada-37xx-cpufreq.c | ||
| bmips-cpufreq.c | ||
| brcmstb-avs-cpufreq.c | ||
| cppc_cpufreq.c | ||
| cpufreq_conservative.c | ||
| cpufreq_governor_attr_set.c | ||
| cpufreq_governor.c | ||
| cpufreq_governor.h | ||
| cpufreq_ondemand.c | ||
| cpufreq_ondemand.h | ||
| cpufreq_performance.c | ||
| cpufreq_powersave.c | ||
| cpufreq_stats.c | ||
| cpufreq_userspace.c | ||
| cpufreq-dt-platdev.c | ||
| cpufreq-dt.c | ||
| cpufreq-dt.h | ||
| cpufreq-nforce2.c | ||
| cpufreq.c | ||
| davinci-cpufreq.c | ||
| e_powersaver.c | ||
| elanfreq.c | ||
| freq_table.c | ||
| gx-suspmod.c | ||
| highbank-cpufreq.c | ||
| ia64-acpi-cpufreq.c | ||
| imx6q-cpufreq.c | ||
| imx-cpufreq-dt.c | ||
| intel_pstate.c | ||
| Kconfig | ||
| Kconfig.arm | ||
| Kconfig.powerpc | ||
| Kconfig.x86 | ||
| kirkwood-cpufreq.c | ||
| longhaul.c | ||
| longhaul.h | ||
| longrun.c | ||
| loongson1-cpufreq.c | ||
| loongson2_cpufreq.c | ||
| Makefile | ||
| maple-cpufreq.c | ||
| mediatek-cpufreq.c | ||
| mvebu-cpufreq.c | ||
| omap-cpufreq.c | ||
| p4-clockmod.c | ||
| pasemi-cpufreq.c | ||
| pcc-cpufreq.c | ||
| pmac32-cpufreq.c | ||
| pmac64-cpufreq.c | ||
| powernow-k6.c | ||
| powernow-k7.c | ||
| powernow-k7.h | ||
| powernow-k8.c | ||
| powernow-k8.h | ||
| powernv-cpufreq.c | ||
| ppc_cbe_cpufreq_pervasive.c | ||
| ppc_cbe_cpufreq_pmi.c | ||
| ppc_cbe_cpufreq.c | ||
| ppc_cbe_cpufreq.h | ||
| pxa2xx-cpufreq.c | ||
| pxa3xx-cpufreq.c | ||
| qcom-cpufreq-hw.c | ||
| qcom-cpufreq-nvmem.c | ||
| qoriq-cpufreq.c | ||
| raspberrypi-cpufreq.c | ||
| s3c24xx-cpufreq-debugfs.c | ||
| s3c24xx-cpufreq.c | ||
| s3c64xx-cpufreq.c | ||
| s3c2410-cpufreq.c | ||
| s3c2412-cpufreq.c | ||
| s3c2416-cpufreq.c | ||
| s3c2440-cpufreq.c | ||
| s5pv210-cpufreq.c | ||
| sa1100-cpufreq.c | ||
| sa1110-cpufreq.c | ||
| sc520_freq.c | ||
| scmi-cpufreq.c | ||
| scpi-cpufreq.c | ||
| sfi-cpufreq.c | ||
| sh-cpufreq.c | ||
| sparc-us2e-cpufreq.c | ||
| sparc-us3-cpufreq.c | ||
| spear-cpufreq.c | ||
| speedstep-centrino.c | ||
| speedstep-ich.c | ||
| speedstep-lib.c | ||
| speedstep-lib.h | ||
| speedstep-smi.c | ||
| sti-cpufreq.c | ||
| sun50i-cpufreq-nvmem.c | ||
| tango-cpufreq.c | ||
| tegra20-cpufreq.c | ||
| tegra124-cpufreq.c | ||
| tegra186-cpufreq.c | ||
| tegra194-cpufreq.c | ||
| ti-cpufreq.c | ||
| vexpress-spc-cpufreq.c | ||